Legal claims defining the scope of protection, as filed with the USPTO.
1. A decoder for generating a time domain audio signal by waveform decoding, the decoder comprising: a receiver for receiving an encoded data stream; a generator for generating a first subband signal by decoding data values of the encoded data stream, the first subband signal corresponding to a critically sampled subband domain signal representation of the time domain audio signal; a converter for generating a second subband signal from the first subband signal or a processed version thereof by subband processing, the second subband signal corresponding to a non-critically sampled complex subband domain representation of the time domain audio signal; a parametric decoder for parametric decoding parametric data using the second subband signal; and a synthesis filter bank for generating the time domain audio signal from the second subband signal.
2. The decoder of claim 1 wherein each subband of the first subband signal comprises a plurality of sub-subbands and the converter comprises a second synthesis filter bank for generating the subbands of the second subband signals from sub-subbands of the first subband signal.
3. The decoder of claim 2 wherein each subband of the second subband signal comprises an alias band and a non-alias band and wherein the converter comprises a splitter for splitting a sub-subband of the first subband signal into an alias sub-subband of a first subband band of the second subband signal and a non-alias subband of a second subband of the second subband signal, the alias subband and the non-alias subband having corresponding frequency intervals in the time domain signal.
4. The decoder of claim 3 wherein the splitter comprises a Butterfly structure.
5. An audio playing device comprising a decoder according to claim 1 .
6. An encoder for encoding a time domain audio signal, the encoder comprising: a receiver for receiving the time domain audio signal; a first filter bank for generating a first subband signal from the time domain audio signal, the first subband signal corresponding to a non-critically sampled complex subband domain representation of the time domain signal; a parametric encoder for parametrically encoding the time domain audio signal using the first subband signal; a converter for generating a second subband signal from the first subband signal or a processed version thereof by subband processing, the second subband signal corresponding to a critically sampled subband domain representation of the time domain audio signals; and a generator for generating a waveform encoded data stream by encoding data values of the second subband signal.
7. The encoder of claim 6 wherein the converter comprises a second filter bank for generating a plurality of sub-subbands for each subband of the first subband signal.
8. The encoder of claim 7 wherein the second filter bank is oddly stacked.
9. The encoder of claim 7 wherein each subband comprises some alias sub-subbands corresponding to an alias band of the subband and some non-alias sub-subbands corresponding to a non-alias band of the subband; and wherein the converter comprises a combiner for combining alias sub-subbands of a first subband band with non-alias sub-subbands of a second subband, the alias sub-subbands and the non-alias sub-subbands having corresponding frequency intervals in the time domain signal.
10. The encoder of claim 9 wherein the combiner are arranged to reduce an energy in the alias band.
11. The encoder of claim 9 wherein the combiner comprises a signal generator for generating a non-alias sum signal for a first alias sub-subband in the first subband and a first non-alias sub-subband in the second subband.
12. The encoder of claim 11 wherein the combiner comprises a butterfly structure for generating the non-alias sum signal.
13. The encoder of claim 12 wherein at least one coefficient of the butterfly structure is dependent on a frequency response of a filter of the first filter bank.
14. The encoder of claim 9 wherein the converter is arranged to not include data values for the alias band in the encoded data stream.
15. The encoder of claim 6 further comprising a non-alias signal processor for performing non-alias signal processing on the first subband signal prior to the conversion to the second signal.
16. The encoder of claim 6 further comprising a phase compensator for phase compensating the first subband signal prior to the conversion to the second signal.
17. The encoder of claim 6 wherein the first filter bank is a QMF filter bank.
18. An audio recording device comprising an encoder according to claim 6 .
19. A method of generating a time domain audio signal by waveform decoding, the method comprising: receiving an encoded data stream; generating a first subband signal by decoding data values of the encoded data stream, the first subband signal corresponding to a critically sampled subband domain signal representation of the time domain audio signal; generating a second subband signal from the first subband signal or a processed version thereof by subband processing, the second subband signal corresponding to a non-critically sampled complex subband domain representation of the time domain audio signal parametric decoding parametric data using the second subband signal; and a synthesis filter bank generating the time domain audio signal from the second subband signal.
20. A method of encoding a time domain audio signal, the method comprising: receiving the time domain audio signal; a first filter bank generating a first subband signal from the time domain audio signal, the first subband signal corresponding to a non-critically sampled complex subband domain representation of the time domain signal; parametrically encoding the time domain audio signal using the first subband signal; generating a second subband signal from the first subband signal or a processed version thereof by subband processing, the second subband signal corresponding to a critically sampled subband domain representation of the time domain audio signals; and generating a waveform encoded data stream by encoding data values of the second subband signal.
21. A receiver for receiving an audio signal, the receiver comprising: a receiver for receiving an encoded data stream; a generator for generating a first subband signal by decoding data values of the encoded data stream, the first subband signal corresponding to a critically sampled subband domain signal representation of the time domain audio signal; a converter for generating a second subband signal from the first subband signal or a processed version thereof by subband processing, the second subband signal corresponding to a non-critically sampled complex subband domain representation of the time domain audio signal; a parametric decoder for parametric decoding parametric data using the second subband signal; and a synthesis filter bank for generating a time domain audio signal from the second subband signal.
22. A transmitter for transmitting an encoded audio signal, the transmitter comprising: a receiver for receiving a time domain audio signal; a first filter bank for generating a first subband signal from the time domain audio signal, the first subband signal corresponding to a non-critically sampled complex subband domain representation of the time domain signal; a parametric encoder for parametrically encoding the time domain audio signal using the first subband signal; a converter for generating a second subband signal from the first subband signal or a processed version thereof by subband processing, the second subband signal corresponding to a critically sampled subband domain representation of the time domain audio signals; and a generator for generating a waveform encoded data stream by encoding data values of the second subband signal; and a transmitter for transmitting the waveform encoded data stream.
23. A transmission system for transmitting a time domain audio signal, the transmission system comprising: a transmitter comprising: a receiver for receiving the time domain audio signal, a first filter bank for generating a first subband signal from the time domain audio signal, the first subband signal corresponding to a non-critically sampled complex subband domain representation of the time domain signal, a parametric encoder for parametrically encoding the time domain audio signal using the first subband signal; a converter for generating a second subband signal from the first subband signal or a processed version thereof by subband processing, the second subband signal corresponding to a critically sampled subband domain representation of the time domain audio signals, a generator for generating a waveform encoded data stream by encoding data values of the second subband signal, and a transmitter for transmitting the waveform encoded data stream; and a receiver comprising: a receiver for receiving the waveform encoded data stream, a generator for generating a third subband signal by decoding data values of the encoded data stream, the third subband signal corresponding to a critically sampled complex subband domain signal representation of the time domain audio signal, a converter for generating a fourth subband signal from the third subband signal or a processed version thereof by subband processing, the fourth subband signal corresponding to a non-critically sampled complex subband domain representation of the time domain audio signal; a parametric decoder for parametric decoding parametric data using the fourth subband signal; and a synthesis filter bank for generating a time domain audio signal from the fourth subband signal.
24. A method of receiving an audio signal, the method comprising: receiving an encoded data stream; generating a first subband signal by decoding data values of the encoded data stream, the first subband signal corresponding to a critically sampled subband domain signal representation of the time domain audio signal; generating a second subband signal from the first subband signal or a processed version thereof by subband processing, the second subband signal corresponding to a non-critically sampled complex subband domain representation of the time domain audio signal parametric decoding parametric data using the second subband signal; and generating a time domain audio signal from the second subband signal using a synthesis filter bank.
25. A method of transmitting an encoded audio signal, the method comprising: receiving a time domain audio signal; a first filter bank generating a first subband signal from the time domain audio signal, the first subband signal corresponding to a non-critically sampled complex subband domain representation of the time domain signal; parametrically encoding the time domain audio signal using the first subband signal; generating a second subband signal from the first subband signal or a processed version thereof by subband processing, the second subband signal corresponding to a critically sampled subband domain representation of the time domain audio signals; and generating a waveform encoded data stream by encoding data values of the second subband signal; and transmitting the waveform encoded data stream.
26. A method of transmitting and receiving a time domain audio signal, the method comprising: a transmitter: receiving the time domain audio signal, a first filter bank generating a first subband signal from the time domain audio signal, the first subband signal corresponding to a non-critically sampled complex subband domain representation of the time domain signal, parametrically encoding the time domain audio signal using the first subband signal; generating a second subband signal from the first subband signal or a processed version thereof by subband processing, the second subband signal corresponding to a critically sampled subband domain representation of the time domain audio signals, generating a waveform encoded data stream by encoding data values of the second subband signal, and transmitting the waveform encoded data stream; and a receiver: receiving the waveform encoded data stream, generating a third subband signal by decoding data values of the encoded data stream, the third subband signal corresponding to a critically sampled subband domain signal representation of the time domain audio signal, generating a fourth subband signal from the third subband signal or a processed version thereof by subband processing, the fourth subband signal corresponding to a non-critically sampled complex subband domain representation of the time domain audio signal parametric decoding parametric data using the fourth subband signal; and generating a time domain audio signal from the fourth subband signal using a synthesis filter bank.
27. A computer program product for executing the method of claim 19 .
28. A decoder for generating a time domain audio signal by waveform decoding, the decoder comprising: a receiver for receiving an encoded data stream; a generator for generating a first subband signal by decoding data values of the encoded data stream, the first subband signal corresponding to a critically sampled subband domain signal representation of the time domain audio signal; a converter for generating a second subband signal from the first subband signal or a processed version thereof by subband processing, the second subband signal corresponding to a non-critically sampled complex subband domain representation of the time domain audio signal; and a synthesis filter bank for generating the time domain audio signal from the second subband signal, wherein each subband of the first subband signal comprises a plurality of sub-subbands and the converter comprises a second synthesis filter bank for generating the subbands of the second subband signals from sub-subbands of the first subband signal.
29. A method of generating a time domain audio signal by waveform decoding, the method comprising: receiving an encoded data stream; generating a first subband signal by decoding data values of the encoded data stream, the first subband signal corresponding to a critically sampled subband domain signal representation of the time domain audio signal; generating a second subband signal from the first subband signal or a processed version thereof by subband processing, the second subband signal corresponding to a non-critically sampled complex subband domain representation of the time domain audio signal; and generating the time domain audio signal from the second subband signal using a synthesis filter bank, wherein each subband of the first subband signal comprises a plurality of sub-subbands and the step of generating a second subband signal from the first subband signal by subband processing uses a second synthesis filter bank for generating the subbands of the second subband signals from sub-subbands of the first subband signal.
30. A computer program product for executing the method of claim 29 .
31. An encoder for encoding a time domain audio signal, the encoder comprising: a receiver for receiving the time domain audio signal; a first filter bank for generating a first subband signal from the time domain audio signal, the first subband signal corresponding to a non-critically sampled complex subband domain representation of the time domain signal; a converter for generating a second subband signal from the first subband signal or a processed version thereof by subband processing, the second subband signal corresponding to a critically sampled subband domain representation of the time domain audio signals; and a generator for generating a waveform encoded data stream by encoding data values of the second subband signal, wherein the converter comprises a second filter bank for generating a plurality of sub-subbands for each subband of the first subband signal.
32. A method of encoding a time domain audio signal, the method comprising: receiving the time domain audio signal; a first filter bank generating a first subband signal from the time domain audio signal, the first subband signal corresponding to a non-critically sampled complex subband domain representation of the time domain signal; generating a second subband signal from the first subband signal or a processed version thereof by subband processing, the second subband signal corresponding to a critically sampled subband domain representation of the time domain audio signals; and generating a waveform encoded data stream by encoding data values of the second subband signal, wherein the step of generating a second subband signal from the first subband signal by subband processing uses a second filter bank for generating a plurality of sub-subbands for each subband of the first subband signal.
33. A computer program product for executing the method of claim 32 .
Unknown
August 28, 2012
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